User equipment power savings for machine type communications

ABSTRACT

Embodiments of user equipment (UE) and base stations (eNodeB) and method for reducing power consumption in UE in a wireless network are generally described herein. In some embodiments, characteristics of UE including mobility, communication data load, and communication type are used by base stations, MME or other controlling entities to configure power saving features of the UE. Power saving features can include a new Radio Resource Control (RRC) layer state where circuitry is powered off for extended periods of time, extended Discontinuous Reception (DRX) cycles, reduced workloads in existing RRC, EPC Connection Management (ECM) and/or EPS Mobility Management (EMM) states or combinations thereof.

PRIORITY CLAIM

This application is a continuation of U.S. application Ser. No.13/718,334, filed Dec. 18, 2012, which claims priority under 35 USC 119to U.S. Provisional Patent Application Ser. No. 61/646,223, filed May11, 2012, each of which are incorporated herein by reference in theirentirety.

TECHNICAL FIELD

Embodiments pertain to wireless cellular communications. Moreparticularly, embodiments relate to saving power in User Equipment (UE).

BACKGROUND

An ongoing problem in devices that connect to wireless networks is toreduce power consumption during operation. This is particularly true fordevices that rely on batteries for their primary power source. However,there is always a tradeoff between power savings and otherconsiderations such as data throughput or adherence to standards such asthe current 3^(rd) Generation Partnership Project (3GPP) long termevolution (LTE) standard.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates cellular communications in accordance with someembodiments.

FIG. 2 is a block diagram of user equipment (UE) in accordance with someembodiments.

FIG. 3 illustrates UE states in accordance with some embodiments.

FIG. 4 illustrates various discontinuous reception cycles (DRX) inaccordance with some embodiments.

FIG. 5 illustrates UE states in accordance with some embodiments.

FIG. 6 illustrates UE state transition in accordance with someembodiments.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

Various modifications to the embodiments will be readily apparent tothose skilled in the art, and the generic principles defined herein maybe applied to other embodiments and applications without departing fromthe scope of the invention. Moreover, in the following description,numerous details are set forth for the purpose of explanation. However,one of ordinary skill in the art will realize that embodiments of theinvention may be practiced without the use of these specific details. Inother instances, well-known structures and processes are not shown inblock diagram form in order not to obscure the description of theembodiments of the invention with unnecessary detail. Thus, the presentdisclosure is not intended to be limited to the embodiments shown, butis to be accorded the widest scope consistent with the principles andfeatures disclosed herein.

FIG. 1 illustrates an example (portion) of a wireless communicationsnetwork 100 shown in a homogeneous network deployment according to someembodiments. In one embodiment, the wireless communications network 100comprises an evolved universal terrestrial radio access network (EUTRAN)using the 3rd Generation Partnership Project (3GPP) long-term evolution(LTE) standard. The wireless communications network 100 includes a firstenhanced Node B (eNodeB or eNB or base station) 110 and a second eNodeB112.

The first eNodeB 110 (also referred to as eNodeB1, eNB1, a first basestation, or a first macro base station) serves a certain geographic areathat includes at least a first cell 114. A plurality of UEs 116, 118located within the first cell 114 is served by the first eNodeB 110. Thefirst eNodeB 110 communicates with the UEs 116, 118 on a first carrierfrequency 120 (F1) and optionally, one or more secondary carrierfrequencies, such as a second carrier frequency 122 (F2).

The second eNodeB 112 is similar to the first eNodeB 110 except itserves a different cell from that of the first eNodeB 110. The secondeNodeB 112 (also referred to as eNodeB2, eNB2, a second base station, ora second macro base station) serves another certain geographic area thatincludes at least a second cell 124. The plurality of UEs 116, 118located within the second cell 124 is served by the second eNodeB 112.The second eNodeB 112 communicates with the UEs 116, 118 on the firstcarrier frequency 120 (F1) and optionally, one or more secondary carrierfrequencies, such as the second carrier frequency 122 (F2).

The first and second cells 114, 124 may or may not be immediatelyco-located next to each other. However, the first and second cells 114,124 may be situated close enough to be considered neighboring cells,such that the user traffic pattern and UL/DL configuration of one of thefirst or second cells 114, 124 may be relevant to the other cell. Forexample, one of the UE 116, 118 served by the first eNodeB 110 may movefrom the first cell 114 to the second cell 124, in which case a hand-offtakes places from the first eNodeB 110 to the second eNodeB 112 withrespect to the particular UE 116, 118. Further, the inter-cellinterference characteristics can be affected by the UL/DL configurationsin the respective cells. As another example, the respective coverageareas of the first and second cells 114, 124 may be distinct or isolatedfrom each other.

The UEs 116, 118 may comprise a variety of devices that communicatewithin the wireless communications network 100 including, but notlimited to, cellular telephones, smart phones, tablets, laptops,desktops, personal computers, servers, personal digital assistants(PDAs), web appliances, set-top box (STB), a network router, switch orbridge, and the like. The UEs 116, 118 can comprise Release 8, 9, 10,11, and/or later releases. Furthermore, UEs 116, 118 may comprisevarious characteristics pertaining to mobility, communication data load,and communication type. Mobility, for example, may be that normallyassociated with movable devices such as smart phones or the like (e.g.“normal” mobility), or may be more infrequent or nomadic where mobilityoccurs occasionally, if at all, perhaps such as a smart meter, or evenstationary. Communication data load may be characterized with thattypically associated with any UE device. For example, mobile phones,personal computers, etc. all have typical or “normal” datacharacteristics (which may, none the less, vary significantly individualdevice to individual device). Other devices, such as smart meters or thelike, may have only infrequent periods of small amounts of data to besent and/or received (e.g. “limited” data characteristics).Communication type may be adapted specifically, as in the case ofmachine type communications (MTC) or may be more general, such as thatused by a phone where some may be more MTC type of communication andother may carry voice or other data (e.g. human type communicationswhere a person initiates the call or data transfer instead of amachine).

Wireless communication network 100 may also include other elements, forexample one or more Mobility Management Entities (MME), Packet DataNetwork (PDN) Gateway (P-GW), Serving Gateways (S-GW), Home SubscriberServers (HSS) or other network operators or entities. These areillustrated in FIG. 1 as MME, P-GW, S-GW, HSS 126 and indicate thatthese, or other network operator or entities can interact with entitieswithin wireless communication network 100, including, withoutlimitation, eNodeBs 110, 112, UEs 116, 118 or other entities. Giventheir ability to control various aspects of the network or entitieswithin the network, MMEs, P-GW, S-GW, HSS, network operators, eNodeBs orother such entities are sometimes referred to herein as a “controllingentity”.

In FIG. 1, MME and S-GW are connected to eNodeBs (e.g. eNB 110, 112)through S1-MME (for control) and S1-U (for user data), respectively. InFIG. 1, these simply labeled S1, for simplicity. Similarly, otherinterfaces exist that are not explicitly shown. S-GW and P-GW areconnected by an S5 interface. MME and HSS are connected by S6a, and UEand eNB are connected by LTE-Uu (e.g. air interface). The interfaceconnecting eNB 110 and 112 is illustrated in FIG. 1 as X2.

It is understood that the wireless communications network 100 includesmore than two eNodeBs. It is also understood that each of the first andsecond cells 114, 124 can have more than one neighboring eNodeB. As anexample, cell 114 may have six or more neighboring macro cells.

In one embodiment, the UEs 116, 118 located in respective first orsecond cells 114, 124 transmits data to its respective first or secondeNodeB 110, 112 (uplink transmission) and receives data from itsrespective first or second eNodeB 110, 112 (downlink transmission) usingradio frames comprising Orthogonal Frequency-Division Multiple Access(OFDMA) frames configured for time division duplexing (TDD) or frequencydivision duplexing (FDD) operations. Depending on the exactconfiguration, the downlink and uplink communication opportunity(subframe or slots) for an eNodeB to communicate information to aparticular UE will happen at different instants.

FIG. 2 illustrates an example block diagram showing details of each ofeNodeBs 110, 112 and UE 116, 118 according to some embodiments. In theseexamples, eNodeBs 110, 112 and UE 116, 118 include a processor 200, amemory 202, a transceiver 204, one or more antennas 208, instructions206, and possibly other components (not shown) which may depend onwhether the devices is an eNodeB or a UE. While similar from a blockdiagram standpoint, it will be apparent to those of skill in the artthat the configuration and details of operation of eNodeBs 110, 112 andUE 116, 118 are substantially different, as described herein.

The eNodeBs 110, 112 can be similar to each other in hardware, firmware,software, configurations, and/or operating parameters. Differences canalso exist, depending on exact configuration and other factors.Similarly, UE 116 and 118 can be similar to each other in hardware,firmware, software, configurations, and/or operating parameters,although differences can also exist. In one example, UE 116 and 118 aresimilar, while in another example, UE 116 can represent one type of UE,such as a cellular telephone, smart phone, tablet, laptop, desktop,personal computer, server, PDA, web appliance, STB, network router,switch or bridge, or the like, while UE 118 can comprise a differenttype of device, such as a smart meter with different characteristics interms of mobility (e.g. nomadic), communication data load (e.g.infrequent periods of low amounts of data transfer), and/orcommunication type (e.g. MTC).

The processor 200 comprises one or more central processing units (CPUs),graphics processing units (GPUs), accelerated processing units (APUs),or various combinations thereof. The processor 200 provides processingand control functionalities for the eNodeB or the UE, depending on thedevice. Memory 202 comprises one or more transient and static memoryunits configured to store instructions and data for the eNodeB or UE.The transceiver 204 comprises one or more transceivers including, for anappropriate eNodeB or UE, and at least one antenna 208 such as amultiple-input and multiple-output (MIMO) antenna to support MIMOcommunications. For eNodeBs, the transceiver 204 receives uplinktransmissions and transmits downlink transmissions, among other things,from and to the UEs respectively. For UE, the transceiver 204 receivestransmissions from eNodeBs (or other UE in direct link communications)and transmits data back to eNodeBs (or other UE in direct linkcommunications).

The instructions 206 comprises one or more sets of instructions orsoftware executed on a computing device (or machine) to cause suchcomputing device (or machine) to perform any of the methodologiesdiscussed herein. The instructions 206 (also referred to as computer- ormachine-executable instructions) may reside, completely or at leastpartially, within the processor 200 and/or the memory 202 duringexecution thereof by the eNodeB, or UE depending on the device. Theprocessor 200 and memory 202 also comprise machine-readable media.

In FIG. 2, processing and control functionalities are illustrated asbeing provided by processor 200 along with associated instructions 206.However, these are only examples of processing circuitry that compriseprogrammable logic or circuitry (e.g., as encompassed within ageneral-purpose processor or other programmable processor) that istemporarily configured by software or firmware to perform certainoperations. In various embodiments, processing circuitry may comprisededicated circuitry or logic that is permanently configured (e.g.,within a special-purpose processor, application specific integratedcircuit (ASIC), or array) to perform certain operations. It will beappreciated that a decision to implement a processing circuitrymechanically, in dedicated and permanently configured circuitry, or intemporarily configured circuitry (e.g., configured by software) may bedriven by, for example, cost, time, energy-usage, package size, or otherconsiderations.

Accordingly, the term “processing circuitry” should be understood toencompass a tangible entity, be that an entity that is physicallyconstructed, permanently configured (e.g., hardwired), or temporarilyconfigured (e.g., programmed) to operate in a certain manner or toperform certain operations described herein.

FIG. 3 is a block diagram of UE states in accordance with someembodiments. In the example of FIG. 3, UE (such as UE 116 or UE 118) hasoverall UE state description 300 along the top row (e.g. Off, Attaching,Idle/Registered, Connecting to EPC (Evolved Packet Core), Active). Alsoillustrated are states for illustrated for an EPS—Mobility Management(EMM) layer 302, an EPS—Connection Management (ECM) layer 304 and aRadio Resource Control (RRC) layer 306.

The EMM layer 302 has two states. When a UE is switched off or uses adifferent radio access network technology (e.g. GPRS or UMTS) it's stateis EMM Deregistered 308. Once the UE sees an LTE network it tries toregister and if successful the state is changed to EMM Registered 310.At the same time the UE is also assigned an IP address. As a consequenceUE in EMM Registered state 310 always have an IP address. However, theEMM state is only influenced by UE management procedures such as Attach,Detach and Tracking Area Updates. While the UE is in EMM Registered 310,the network knows the location of the UE either on a cell level or atracking area level. Which of the two depends on the connectionmanagement state machine described below.

When a UE is registered (EMM Registered state) it can be in two ECMstates. While a data transfer is ongoing the UE is in ECM Connectedstate 314. For the UE this means that on the radio link a RRC connectionis established. For the network, ECM connected 314 means that both theMobility Management Entity (MME) and the Serving (User Data) Gateway(SGW) have a connection to the mobile device via the S1 interface (thephysical and logical link between the core network and the radio accessnetwork). In ECM connected state 314, the cell level knows the locationof the mobile and cell changes are controlled by handovers.

If there is no activity for some time, the network can decide that it isno longer worthwhile to keep a logical and physical connection in theradio network. The connection management state is then changed to ECMidle 312. The use of the term “idle” does not mean the connectioncompletely goes away. Logically, it is still there but the RRCconnection to the UE is removed as well the S1 signaling and data link.The UE continues to be EMM registered 310 and the IP address it has beenassigned remains in place. In ECM idle state 312 the location of the UEis only known down to the tracking area level and the UE performs cellchanges autonomously without any signaling exchanges with the network

From the base station (eNB or the like) and UE point of view there is alot of room for maneuvering between ECM connected 314 and ECM idle 312.While a lot of data is exchanged, the air interface can be fullyactivated for the UE so it has to continuously listen for incoming data.In times of lower activity or even no activity at all, the base stationcan activate a discontinuous reception (DRX) mode so the UE devices canpower down its transceivers for some time. The power down cycles rangefrom milliseconds to a few seconds (2560 msec in the currentstandard—the longest DRX cycle defined). For some embodiments,modifications to the DRX cycle are illustrated in FIG. 4 and discussedbelow.

From a UE point of view the main difference between being in ECMConnected state 314 with a DRX cycle the length of a paging interval andbeing in ECM Idle state 312 without a radio interface connection is howit's mobility is controlled. In ECM Connected state 314, handovers areperformed. In ECM Idle state 312, UE can change its serving cellautonomously and only has to report to the network when it leaves thecurrent tracking area. For many UE, the base station is likely to keepthe UE in ECM Connected state 314 for as long as possible by using DRXso data transfers can be resumed very quickly before cutting the linkentirely and setting the state to ECM Idle 312. Thus, power savingsopportunities using DRX under the present standard are limited.

The RRC protocol is responsible for the main controlling functionsbetween UE and eNB, for example radio bearer establishment, lower layerconfiguration and transfer of NAS information. This entails: 1)broadcasting system level information; and 2) maintaining connectionlayer bi-directional control. RRC has two states, RRC Idle 316 and RRCConnected 318. In the RRC Connected state 318, the RRC manages thetransmission/reception of all UE and control data in the upload/downloadslots (UL/DL). In the RRC Idle state 316, RRC does various tasks forradio link management such as: 1) cell selection/reselection; 2)monitoring paging channels, acquiring system information broadcast in acell. Under the current 3GPP standard, opportunities for power savingsare limited, even during the RRC Idle state 416.

FIG. 4 illustrates an example DRX cycle, according to some embodimentsof the present invention. As illustrated in FIG. 4, the DRX cycle has an“on” time 400 and “off” time 402. During the off time, the UE isrelieved of responsibilities such as monitoring PDCCH (DL controlchannel), in an attempt to save power. Due to decreases in overallbandwidth produced by a longer DRX cycle time, some UE characteristicsmay demand a shorter DRX cycle 404, rather than a long DRX cycle.

However, for certain UE characteristics, even the long DRX cycle may notprovide sufficient power savings. Furthermore, a base station bias tokeeping UE in the ECM Connected state adds to the problem. This isparticularly true for UE with certain characteristics in mobility (e.g.nomadic), communication data load (e.g. infrequent periods of lowamounts of data transfer), and/or communication type (e.g. MTC). SomeMTC type examples are described in 3GPP TR 22.888, Study on Enhancementsfor MTC, and include smart grid, automotive, mobile rescue team,device-to-device type communications, cargo tracking, and otherexamples.

In situations where long DRX cycle do not provide sufficient powersavings, a new DRX cycle 406 extends the “off” time to significantamounts of time, from the few seconds of the existing standard tomultiple deci-hours or even longer in the case of appropriate UE. Such anew DRX cycle can be defined within the current DRX cycles and pagingcycles or as part of a new Passive Paging message. Additionally, oralternatively, the new Passive Paging message (or changes to the currentDRX cycles and paging cycles) may affect additional behavior of UEs,such as UE 116 and/or UE 118. In one example, Passive Paging messages(or changes to the current DRX cycles and paging cycles) allow the UE tomake less frequent Radio Resource Management (RRM) measurements if theUE is stationary most of the time. Additionally, or alternatively, thePassive Paging message may reduce other procedures the UE may need todo, or change the data the UE keeps stored, depending on thecharacteristics of the UE.

According to some embodiments, a controlling entity, such as eNodeB 110or eNodeB 112 of FIG. 1 or a MME, can receive (or otherwise know) UEcharacteristic information including mobility characteristic informationand/or data transmission characteristic information (e.g. communicationdata load and/or communication type). Based on the UE characteristicinformation, the controlling entity can decide on a power savingsconfiguration for the UE, which modify UE behavior while in the RRC idlestate 316 and/or the ECM Idle state 308. Modifying the behavior of theUE while in the RRC Idle state 316 and/or ECM Idle state 312 can includemodifying the DRX cycle time to be outside the parameters of theexisting standard and/or modifying the work the UE performs (or data theUE keeps) during the RRC Idle state 316 and/or ECM Idle state 312. Asnoted above, these modifications may be communicated to the UE through aPassive Paging message, or a message according a current standard (e.g.current paging message or other message).

FIG. 5 is a block diagram of a UE in accordance with some embodiments.The example of FIG. 5 adds additional states to those described in FIG.3, namely ECM Deep Idle state 520 and RRC Deep Idle state 522. These twostates, either singly or in conjunction with one another, representadditional power savings functionality that can be utilized either aloneor in conjunction with other power savings functionality as describedabove in conjunction with FIG. 3 and/or FIG. 4. ECM Deep Idle state 520and/or RRC Deep Idle state 522 reduce the circuitry powered up, the datastored, the processing load (e.g. procedures performed) or somecombination thereof, as described more fully below.

FIG. 6 illustrates examples of an RRC Deep Idle state (such as RRC DeepIdle state 522) and its relationship between an RRC Idle state (such asRRC Idle state 516) and an RRC Connected state (such as RRC Connectedstate 518) according to some examples in more detail.

FIG. 6 illustrates RRC Connected state 610. In this state, various UEactivities can are performed. Examples of UE activities include activedata transmission and/or reception, monitoring network paging activity,and/or monitoring system information broadcasts. In addition, thenetwork controls mobility of the UE. Other optional activities caninclude DRX configuration (including an extended DRX cycle like 406 ofFIG. 4), Deep Idle state 614 configuration (discussed more fully below),and configuration for RRC Idle state 612 workload reduction (e.g.reducing the procedures performed during RRC Idle state 614, and/orreducing the data or other information kept by UE while in the RRC Idlestate 614).

The UE enters RRC Idle state 612 in a variety of ways, such as when RRCConnection Release (illustrated by 616) is received from an eNodeB (suchas eNodeB 110 or eNodeB 112). While in RRC Idle state 612, the UE canperform various activities such as monitoring network paging activity,and/or monitoring system information broadcasts. The UE controlsmobility in the RRC Idle state 612. Other optional activities orcharacteristics can include Deep Idle state 614 configuration (discussedmore fully below). Finally, depending on the configuration of RRC Idlestate 612, RRC Idle may reduce the procedures performed and/or the dataor other information kept by the UE while in the RRC Idles state 614.

As examples of workload reduction (e.g. reducing the proceduresperformed and/or the data or other information kept by the UE), insituations where the UE has nomadic mobility or is stationary (perhapsin the case of a smart meter, network router, or other device that movesonly occasionally or not at all), the normal cell selection/reselectionprocedures can be modified or eliminated all together. Modification caninclude either eliminating things that are typically done as part of theprocedure (e.g. RRM measurements), or reducing the frequency and/orchanging the methodology associated with them. As an example only, if adevice is nomadic or stationary, mobility related procedures may onlyneed to be rarely performed. Even then, cell selection may simply usethe stored value of the prior cell (as that is the most likely location)until additional information illustrates a need for other cell selectionprocedures to be performed. Finally, it may be that security or otherinformation normally kept and/or updated as part of the RRC Idle state612 can be reduced or eliminated.

Transition from the RRC Idle state 612 or RRC Connected 610 to RRC DeepIdle state 614 can be based on a variety of triggers (illustrated by618). One trigger may be information received as part of RRC ConnectionRelease (like 616). Other triggers may be the expiration of aninactivity timer (which happens when there is no UL/DL data detectedduring the “on” portion of a DRX cycle), or expiration of a length oftime or some other mechanism.

In RRC Deep Idle state 614, the intent is to reduce power consumption toa minimum. Therefore, various processing circuitry can be put in a lowpower or off position. During such time, no or perhaps reduced mobilitymeasurements may be made, no paging may be monitored, and no systeminformation broadcasts may be monitored, or combinations thereof. In oneembodiment, transceiver and related processing circuitry are poweredoff. In another embodiment, provisions are made for paging or otherinformation directed to the UE while in the RRC Deep Idle state 614.Such received information can be either discarded (such as when thetransceiver and related circuitry is powered off) or retained in abuffer or other storage area for later processing when the UEtransitions out of RRC Deep Idle state 614.

UE may transition out of the RRC Deep Idle state 614 in a variety ofways, depending on the particular example. In one example, transitionfrom RRC Deep Idle 614 to RRC Idle 612 occurs upon expiration of aparticular length of time (illustrated by 620). This length of timemaybe configured either by a controlling entity (such as MME or eNodeB)or may be defined at the time of manufacture. Furthermore, it may bemore or less static, depending on the characteristics of the UE, or maybe dynamically configured to suit the characteristics and needs of thecurrent time. In one example, the length of time is configured by aneNodeB as part of the RRC Connection Release. In another example, thelength of time is configured by an eNodeB in a paging message (Passivepaging or other paging). In yet another example, the length of time canbe configured as part of an of Open Mobile Alliance Device Management(OMA-DM) procedure or as part of subscriber identity module,over-the-air (SIM-OTA) procedure or as part of an HLR/HSS subscription.In still another example, the length of time can be configured as partof a broadcast by an eNodeB for a special category of devices (perhapsthose with certain mobility characteristic information and/or datatransmission characteristic information (e.g. communication data loadand/or communication type)).

Alternatively, or additionally, UE may transition out of the RRC DeepIdle state 614 when the UE has UL data that it determines should notwait until the expiration of the length of time. In such a situation,transition may be out of RRC Deep Idle state 614 to RRC Connected state610 (illustrated by 622) or to RRC Idle state 612 and from there to RRCConnected state 610 (illustrated by 624).

Although not illustrated in FIG. 6, some embodiments may transitiondirectly from RRC Connected 610 to RRC Deep Idle 614 or may pass throughRRC Idle 612, either as part of a defined set of circumstances or as analternative to transitioning from RRC Connected 610 to RRC Idle 612 andthen to RRC Deep Idle 614.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b)requiring an abstract that will allow the reader to ascertain the natureand gist of the technical disclosure. It is submitted with theunderstanding that it will not be used to limit or interpret the scopeor meaning of the claims. The following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate embodiment.

The term “computer readable medium,” “machine-readable medium” and thelike should be taken to include a single medium or multiple media (e.g.,a centralized or distributed database, and/or associated caches andservers) that store the one or more sets of instructions. The termsshall also be taken to include any medium that is capable of storing,encoding or carrying a set of instructions for execution by the machineand that cause the machine to perform any one or more of themethodologies of the present disclosure. The term “computer readablemedium,” “machine-readable medium” shall accordingly be taken to includeboth “computer storage medium,” “machine storage medium” and the like(tangible sources including, solid-state memories, optical and magneticmedia, or other tangible devices and carriers but excluding signals perse, carrier waves and other intangible sources) and “computercommunication medium,” “machine communication medium” and the like(intangible sources including, signals per se, carrier wave signals andthe like).

It will be appreciated that, for clarity purposes, the above descriptiondescribes some embodiments with reference to different functional unitsor processors. However, it will be apparent that any suitabledistribution of functionality between different functional units,processors or domains may be used without detracting from embodiments ofthe invention. For example, functionality illustrated to be performed byseparate processors or controllers may be performed by the sameprocessor or controller. Hence, references to specific functional unitsare only to be seen as references to suitable means for providing thedescribed functionality, rather than indicative of a strict logical orphysical structure or organization.

Although the present invention has been described in connection withsome embodiments, it is not intended to be limited to the specific formset forth herein. One skilled in the art would recognize that variousfeatures of the described embodiments may be combined in accordance withthe invention. Moreover, it will be appreciated that variousmodifications and alterations may be made by those skilled in the artwithout departing from the scope of the invention.

1. (canceled)
 2. An apparatus for a user equipment (UE), the apparatuscomprising: memory; and processing circuitry to: enter a power savingmode, in which the UE is not available for paging, upon expiration of atimer after a transition from an Evolved Packet System (EPS) ConnectionManagement (ECM) CONNECTED state to an ECM_IDLE state, while remainingin an EPS Mobility Management (EMM) REGISTERED state, wherein a mobilitymanagement entity (MME) knows a location of the UE to a cell level inthe ECM CONNECTED state and wherein the MME knows the location of the UEto a tracking area level in the ECM IDLE state.
 3. The apparatus ofclaim 2, wherein the processing circuitry is configured to exit thepower saving mode subsequent to determining to transmit uplink data. 4.The apparatus of claim 2, wherein the processing circuitry is configuredto exit the power saving mode to provide a tracking area update (TAU).5. The apparatus of claim 2, further including: transceiver circuitry,and two or more antennas coupled to the transceiver circuitry.
 6. Theapparatus of claim 2, wherein the apparatus is included in a deviceconfigured to perform machine-type communications (MTC).
 7. Theapparatus of claim 2, wherein the processing circuitry is furtherconfigured to control the discontinuous reception cycle (DRX).
 8. Theapparatus of claim 2, wherein UE data transmission characteristicscomprise either normal data characteristics associated with non-MachineType Communications (non-MTC) or limited data characteristics associatedwith Machine Type Communications (MTC).
 9. A non-transitorycomputer-readable storage medium that stores instructions for executionby processing circuitry of a user equipment (UE), the instructions toconfigure the UE to: enter a power saving mode, in which the UE is notavailable for paging, upon expiration of a timer after a transition froman Evolved Packet System (EPS) Connection Management (ECM) CONNECTEDstate to an ECM_IDLE state, while remaining in an EPS MobilityManagement (EMM) REGISTERED state.
 10. The non-transitorycomputer-readable medium of claim 9, wherein a mobility managemententity (MME) knows a location of the UE to a cell level in the ECMCONNECTED state and wherein the MME knows the location of the UE to atracking area level in the ECM IDLE state.
 11. The non-transitorycomputer-readable storage medium of claim 9, wherein a value for thetimer is configured by a Mobility Management Entity (MME).
 12. Thenon-transitory computer-readable storage medium of claim 9, wherein theinstructions configure the UE to exit the power saving mode subsequentto determining to transmit uplink data.
 13. The non-transitorycomputer-readable storage medium of claim 9, wherein the instructionsconfigure the UE to exit the power saving mode to provide a trackingarea update (TAU).
 14. The non-transitory computer-readable storagemedium of claim 9, wherein the UE is included in a device configured toperform machine-type communications (MTC).
 15. The -transitorycomputer-readable storage medium of claim 9, wherein the instructionsconfigure the UE to control the discontinuous reception cycle (DRX). 16.The -transitory computer-readable storage medium of claim 9, wherein UEdata transmission characteristics comprise either normal datacharacteristics associated with non-Machine Type Communications(non-MTC) or limited data characteristics associated with Machine TypeCommunications (MTC).
 17. A method comprising: entering an EvolvedPacket System (EPS) Connection Management (ECM) IDLE state; enter apower saving mode, in which the UE is not available for paging, uponexpiration of a timer after entering the ECM_IDLE state, while remainingin an EPS Mobility Management (EMM) REGISTERED state.
 18. The method ofclaim 17, wherein a mobility management entity (MME) knows a location ofthe UE to a cell level in an ECM CONNECTED state and wherein the MMEknows the location of the UE to a tracking area level in the ECM IDLEstate.
 19. The method of claim 17, further comprising: exiting the powersaving mode subsequent to determining to transmit uplink data.
 20. Themethod of claim 19, further comprising: providing a tracking area update(TAU) after exiting the power saving mode.